Arduino Si4703 (and family) Library

This library is intended for use with the SparkFun Si4703 Evaluation or Breakout
Board, however it should work with most Si470x chips that share the same command
language. At the time of this writing, the list includes: Si4700->Si4703.

To the furthest extent that this is legally possible, the fork maintained by
Radu - Eosif Mihailescu and published here https://github.com/csdexter/Si4703
is hereby released under the LGPL version 3.
To the furthest extent that this is legally enforceable, the copyright remains
with the authors listed above.

See the example sketches to learn how to use the library in your code. Note
that RDS decoding functionality is implemented by the RDSDecoder library.

HARDWARE NOTES:
 * The Si4703 is a 3.3V I/O chip whereas the Arduino Uno/Mega are 5V I/O. This
   means you will need to use logic level shifters if you are trying to use
   either of the SparkFun boards with the latter. The chip technically
   supports two interfaces, I2C and a one-wire version of SPI. Since the latter
   is non-trivial to bit-bang on the Arduino (not being true SPI), this library
   only uses I2C to talk to the chip. In that context, ONLY the BOB-11955 will
   work for logic level shifting the I2C lines if using a 5V I/O Arduino. For
   the other lines (#RST, #SEN and #INT), you can use any of the level
   translator boards in SparkFun's offering. Note that #RST is special because
   it already has a pull-down on board, which means the very old
   resistor divider-based translator will not work -- just use a 10K resistor
   in series with the #RST line in that case.
 * The library assumes an external 32768Hz crystal oscillator is present and 
   properly connected to the chip, as detailed in the datasheet. If that's not
   the case, you will have to tell the library and provide the reference clock
   yourself via other means.
 * Quick connection reference:
   I2C Mode, Si4703 -> Arduino:
     SDIO      -> SDA     (Arduino bidirectional)
     SCLK      -> SCL     (Arduino output)
     #SEN      -> SS      (Arduino output or tied high to select I2C mode)
     #RESET    -> D9      (Arduino output)
     GPO1      -> left floating
     GPO2/#INT -> D2/INT0 (Arduino input)
                  or (left floating, if not using interrupts)
     GPO3      -> left floating

For general questions and updates on this library please contact the fork
maintainer at <[email protected]>.